An example of a feeder of this type is shown in U.S. Pat. Nos. 4,660,508 and 4,790,266 of the present inventor and this type of feeder has become very successful and is widely known as a wet/dry feeder in view of the fact that the animal can take dry feed from the shelf of the feeder or can apply water into feed discharged into the trough to take the feed in the trough in wet condition.
The intention is that the animals themselves control the amount of water supply by providing nipples in the trough which can be actuated by the animal to discharge water into the trough to mix with the feed. One advantage of this type of feeder is that the animals can mix the feed to the consistency they prefer so that they are encouraged to eat as much as possible by ensuring that they are not discouraged from eating by the feed being too dry or too wet. It has been found that this type of feeder has considerable increase in weight gain for the animals over conventional dry feeders.
Feeders of this type can either be double sided that is the feeder has two sides each of which can be accessed by a different set of animals so that generally the feeder is placed in a fence line to supply feed to animals in two separate panic. Other type of feeders are however single sided so that they have generally a vertical rear wall with the trough presented forwardly of that rear wall and the animals accessing the feeder only from the trough side of the rear wall.
In U.S. Pat. No. 5,640,926 of the present inventor issued Jun. 24, 1997 is disclosed a feeder of the above type. In this feeder, the height of the shelf from the trough is adjustable so as to accommodate a change in size of the animals from a smaller size up to a larger size as the animals grow.
In U.S. Pat. No. 5,967,083 of the present inventor issued Oct. 19, 1999 is disclosed a feeder of the above type. In this feeder, the height of the side wall of the trough from the base of the trough is adjustable so as to accommodate a change in size of the animals from a smaller size up to a larger size as the animals grow.
Feeders of this type are designed and manufactured for hogs from weanlings up to finishers and the above adjustable types can be used in some circumstances to accommodate growth or different feeders of fixed dimensions for different sizes of animal may be provided.
One problem which has existed since the invention of this type of feeder is that very young weanlings have a tendency to play with or activate the water nipples due to their recent suckling and hence they release too much water into the trough so that the feeder becomes overwhelmed with consequent blocking of the feed supply to the shelf. Of course the presence of the excess water also inhibits the feed intake of the animals. It has been noted that after a few days or weeks the animals lose this tendency and manage the water supply by activating the nipples only when they require as do older animals. However the difficulties during the first days or weeks have dramatically reduced the acceptability of the feeder for weanlings despite its known feed uptake advantages. Many operators will therefore not use this type of feeder for weanlings due to the repeated attention and maintenance which is required during this initial stage.
Many attempts have been made to overcome this problem during the past twenty years by controlling the water supply to the nipples so that the amount dispensed is reduced. Up to now all of these attempts have been unsuccessful and a significantly reduced percentage of feeders of this type are used for weanlings. Only those operators who are willing to accept the repeated maintenance to remove excess water and to clean the resulting mess and blockage problems are able to use this type successfully.